Genetically engineered mice have become an essential tool in biomedical research. They are crucial tools for studying development of the skin and its appendages. In addition, these mouse models have become indispensible for creating models of human skin disorders, including inherited and aquired skin disorders and skin cancer. Generating transgenic or knockout mice requires specialized skills and expensive equipment. Consequently, very few laboratories have the ability to generate these valuable research models. The Transgenic and Gene Targeting (TGT) Core at the University of Colorado Denver offers a comprehensive set of services which enables investigators to generate genetically engineered mice. These services include the generation of transgenic mice via pronuclear injections, and gene targeting experiments that include the entire process from generating recombinant ES cells to the production of chimeric mice. All that is required from the investigators to initiate these experiments is a transgenic vector or gene targeting vector. Furthermore, our core offers extensive consultation services to help investigators with the development of a research plan, including vector design, animal design, and the analysis of genetically engineered mice. 23 investigators of the Skin Disease Research Core Center (UCD-SDRC) are planning to use our core services to generate mouse models to study skin biology or skin diseases. Core Center support for our core will provide these investigators with subsidized access to the full set of our services, and thus facilitate their research.